The journal Medicine (Baltimore) recently published the results of a meta-analysis of randomized and controlled trials evaluating the effect of curcumin on inflammatory markers and disease activity among people with rheumatoid arthritis. This meta-analysis included 7 trials, all fairly small, ranging from 24 to 90 participants each, for a total of 333. The majority of the trials were rated to have moderate to high methodological quality, and most had a low risk of bias.
Five studies reported the commonly used marker of disease activity, DAS28 (Disease Activity Score in 28 joints), demonstrating a pooled reduction (weighted mean difference (WMD) of –1.47) from curcumin compared to controls, a clinically meaningful improvement. The studies that examined the effects of curcumin on inflammatory markers also showed significant reductions compared to the control, including rheumatoid factor (WMD = –24.15), erythrocyte sedimentation rate (WMD = –31.26), and C-reactive protein (WMD = –0.93).
The studies included in this meta-analysis are small but encouraging, and similar to results reported in a recent umbrella review published in Frontiers in Pharmacology, which also cited reductions in DAS28, rheumatoid factor, VAS (visual analogue scale) pain, and swollen and tender joint counts among people with rheumatoid arthritis. As the authors of the meta-analysis point out, curcumin inhibits key inflammatory pathways such as nuclear factor-kappa B and Janus kinase/signal transducer and activator of transcription, providing plausible biological mechanisms for its benefits (reviewed here). Additionally, the seven included studies had variation in their dosing regimens and formulations, and it seems quite likely that, given curcumin’s poor bioavailability, forms of curcumin with higher bioavailability, given at sufficient doses, would be the most effective.